Cocaine abuse is a major health problem in the United States and has reached epidemic proportions in recent years as more addictive forms of the drug have become available. In addition to the many sociological problems arising from cocaine abuse, there are adverse medical consequences from the use of this drug, such as acute intoxication marked by convulsions and cardiac arrhythmias. Chronic cocaine use is generally associated with increasing toxicity and behavioral pathology, and can result in the progressive development of seizures. Also, addiction to intravenous cocaine use is likely to increase the risk of AIDS, both through needle sharing and through the immuno-suppressive effects of the drug.
The mechanisms underlying the reinforcing effects of cocaine is not fully understood, particularly since this drug exhibits activities as both a potentiator and depressant of catecholaminergic systems. Thus, the initial effects of cocaine are known to enhance the activity of such neurotransmitters as dopamine, norepinephrine, epinephrine and serotonin, for example, which provides an immediate inducement to the use of the drug. Subsequent effects include depressing the biological characteristics of such neurotransmitters by blocking their uptake in the nervous system, which serves as an recurring inducement to undertake the repeatedly use of cocaine. This dual-action symptomology of cocaine is difficult to disrupt since the fundamental physiological and psychological processes responsible for the cocaine habituation syndrome remain largely unidentified. However, there is a strong consensus that dopaminergic neural systems play a critical role in cocaine reinforcement.
Although dopaminergic antagonists have shown some success in blocking the reinforcing effects of cocaine in experimental animals, there is at present no uniformly effective pharmacotherapy for cocaine dependence. Attempts to treat users of cocaine by administering a less harmful or less pleasurable drug in its place have yielded inconsistent results. Such treatment programs can result in a substitute addiction and may even stimulate relapse to cocaine abuse. In addition, abstinent treatment programs have met with limited success, largely because of the unpleasant symptoms accompanying cocaine withdrawal. These withdrawal symptoms include irritability, anxiety, depression, headaches and various other pains throughout the body. In many cases, the pain and discomfort become so severe upon cessation of cocaine dependency that abstinent persons abruptly return to the abused drug in an attempt to alleviate withdrawal symptoms.
There is therefore a substantial need to provide a non-addictive therapeutic treatment for cocaine abuse that is not only capable of interrupting the cocaine habituation syndrome, but also has the capability of alleviating the symptoms attendant upon withdrawal.